Lilburn is home to one of nearly 400 USArray seismic/infrasound stations in use in the eastern United States. They are part of a large-scale project named “Earthscope,” an initiative funded by the National Science Foundation that studies the Earth’s interior beneath North America.
The stations are mainly deployed to record seismic waves generated from earthquakes, but their sound sensors can record ultra long-period sound waves, also known as infrasound waves.
The human ear cannot hear these infrasound signals. However, by playing the data faster than true speed, Georgia Tech faculty member Zhigang Peng increased the sound waves’ frequency to audible levels. The Incorporated Research Institutions for Seismology's Data Managment Center provided the data.
“The sound started at about 10 hours after the explosion and lasted for another 10 hours in Georgia,” said Peng, an associate professor in the School of Earth and Atmospheric Sciences. He’s confident that the sound is associated with the meteor impact because a slow propagation of the sound waves can be seen across the entire collection of USArray stations, as well as other stations in Alaska and polar regions.
“They are like tsunami waves induced by large earthquakes,” Peng added. “Their traveling speeds are similar, but the infrasound propagates in the atmosphere rather than in deep oceans.”
Scientists believe the meteor was about 55 feet in diameter, weighed more than 7,000 tons and raced through the sky at 40,000 miles an hour. Its energy was estimated at 30 nuclear bombs. More than 1,500 people were hurt.
Using the same sonification process, Peng also converted seismic waves from North Korea’s nuclear test on February 12 and an earthquake in Nevada the next day. Each registered as a 5.1 magnitude event but created different sounds. The measurements were collected by seismic instruments located about 100 to 200 miles from each event. For further comparison, Peng has also created a seismic recording of the meteor impact at a similar distance.
“The initial sound of the nuclear explosion is much stronger, likely due to the efficient generation of compressional wave (P wave) for an explosive source,” said Peng. “In comparison, the earthquake generated stronger shear waves that arrived later than its P wave.”
Peng says the seismic signal from the meteor is relatively small, even after being amplified by 10 times. According to Peng, this is mainly because most of the energy from the meteor explosion propagated as the infrasound displayed in the initial sound clip. Only a very small portion was turned into seimsic waves propagating inside the Earth.
This isn’t the first time Peng has converted seismic data into audible files. He also sonified 2011's historic Tohoku-Oki, Japan, earthquake as it moved through the Earth and around the globe.
The seismic and sound data generated by the meteor impact and other sources can be used to demonstrate their global impact. Scientists are also using them to better understand their source characterizations and how they propagate above and inside the earth.
Jason Maderer | Newswise
NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center
The melting ice makes the sea around Greenland less saline
16.10.2017 | Aarhus University
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences